Abstract: A method for preparing a crystal of 4-[(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)carbamoyl]benzoic acid having a single endothermic peak approximately at 233° C. in differential scanning calorimetry, which comprises the step of recrystallizing a crystal of 4-[(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)carbamoyl]benzoic acid from a mixture of water and ethanol. The method enables selective preparation of type-II crystals which are stable against physical impact. The resulting crystals are free from highly toxic hexane as a residual solvent, and preferably used as an active ingredient of pharmaceuticals.

Abstract: A method for preparing a crystal of 4-[(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)carbamoyl]benzoic acid having a single endothermic peak approximately at 233° C. in differential scanning calorimetry, which comprises the step of recrystallizing a crystal of 4-[(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)carbamoyl]benzoic acid from a mixture of water and ethanol. The method enables selective preparation of type-II crystals which are stable against physical impact. The resulting crystals are free from highly toxic hexane as a residual solvent, and preferably used as an active ingredient of pharmaceuticals.

Abstract: A zirconium alloy which has good creep strength and bending properties as well as improved corrosion resistance in nitric acid solutions of low, medium, and high concentrations and which can withstand stress corrosion cracking in highly concentrated nitric acid solutions even under a high anodic potential is disclosed. The zirconium alloy consists essentially of, by weight percent:one or both of Ti: 5.0-30% and Ta: 1.0-20%,Fe: not greater than 0.3%, Cr: not greater than 0.1%,Oxygen: 0.05-0.2%, N: not greater than 0.45%,H : not greater than 0.01%,one or more of W, V, and Mo: 0-3.0% in total, and the balance Zr and inevitable impurities.

Abstract: A nickel-chromium alloy excellent in a stress corrosion cracking resistance which is obtained by carrying out an annealing treatment under specific conditions, said alloy having the following composition:______________________________________ in terms of % by weight, ______________________________________ 0.04% or less of C; 1.0% or less of Si; 1.0% or less of Mn; 0.030% or less of P; 0.02% or less of S; 40 to 70% of Ni; 25 to 35% of Cr; 0.1 to 0.5% of Al; 0.05 to 1.0% of Ti; 0.5 to 5.0% in all of one or more of Mo, W and V, and ______________________________________the residue comprising substantially Fe. A nickel-chromium alloy further including 0.2 to 5.0% of Nb subject to Ti=0.2 to 1.0% and Nb/C=10 to 125.

Abstract: An alloy for heat transfer pipes excellent in an alkali stress corrosion cracking resistance which is obtained by heating and retaining said alloy at a temperature within the range of a temperature (T.degree.C.), at which a carbide in said alloy is thoroughly solubilized, to T+100.degree. C. for 1 minute or more; cooling it once to a level of 200.degree. C. or less; and carrying out a thermal treatment under conditions within a hatched range Z in FIG. 2, said alloy comprising: in terms of % by weight, 0.15% or less of C; 1.0% or less of Si; 1.0% or less of Mn; 25 to 35% of Cr; 40 to 70% of Ni; 0.5% or less of Al; 0.01 to 1.0% of Ti; 0.5 to 5.0%, in all, of one or more of Mo, W and V; 0.30% or less of P; 0.020% or less of S; and the residue of Fe and impurities.

Abstract: A method for a thermal treatment of a nickel based alloy, characterized in that said nickel based alloy for a material which will be subjected to a high-temperature and high-pressure water or vapor comprises, in terms of % by weight, 58% or more of Ni, 25 to 35% of Cr, 0.003% or less of B, 0.012 to 0.035% of C, 1% or less of Mn, 0.5% or less of Si, 0.015% or less of P, 0.015% or less of S, and the residue of Fe and usual impurities; in a first thermal treatment process, said nickel based alloy is heated and retained at a temperature of T.degree. C. to (T+100).degree.C. and is cooled at a cooling rate of a furnace cooling rate or more; and in a second thermal treatment process, said nickel based alloy is then retained at a temperature of 600.degree. to 750.degree. C. and at a temperature within a sensitization recovery range for a period of 0.1 to 100 hours and is cooled at a cooling rate of said furnace cooling rate or more.

Abstract: An austenitic stainless steel exhibiting improved resistance to corrosion caused by nitric acid is disclosed, which consists essentially of:C: not more than 0.03% by weight, Si: 2-6% by weight,Mn: 0.1-8% by weight, Cr: 20-35% by weight,Ni: 17-50% by weight, Mg: not more than 0.02%,at least one of Nb, Ti and Ta in the total amount of 8.times.C(%) or more, but 1.0% by weight or less,S: not more than 0.003% by weight,Oxygen: not more than 0.003% by weight,N: not more than 0.03% by weight,P: not more than 0.02% by weight,Fe and incidental impurities: balancethe composition further satisfying the following relationships;-10.ltoreq.Ni(Bal).ltoreq.-0.1Cr(%).gtoreq.(7/4)Si(%)+16.5Mg(%)-0.75.times.S(%)-1.5.times.Oxygen(%).gtoreq.0wherein, Ni(Bal)=30.times.C(%)+0.5.times.Mn(%)+Ni(%)+8.2-1.1.times.[1.5.times.Si(%) +Cr(%)].

Abstract: A dual-phase stainless steel exhibiting improved resistance to corrosion caused by nitric acid is disclosed, which consists essentially of:C: not more than 0.02% by weight, Si: 2-6% by weight,Mn: 0.1-2% by weight, Cr: 20-35% by weight,Ni: 3-27% by weight, P: not more than 0.02% by weight,N: not more than 0.30% by weight,Fe and incidental impurities: balance the amount of ferrite to be 30-70% by volume.

Abstract: Electrolytic descaling of a steel wire is carried out at a high current density by a non-contact flow method in the presence of ferrous ions in the electrolyte to prevent the consumption of electrodes.

Abstract: Mill scales formed on the surface of a steel wire are continuously removed by causing the wire to pass through a plurality of pairs of electrodes which are connected to an electric power source and arranged in series in an electrolytic cell without contacting the electrodes. This apparatus is applicable in a continuous stretching equipment.

Abstract: A device for cross-linking of coating material such as rubber or plastic having a vertical or inclined cross-linking tube including a heating portion and a succeeding cooling portion, said heating portion comprising at the side thereof a gas circulating passage having a gas supply device, a gas heating device, a gas cooling device and a filter, said gas circulating passage communicating with an exhaust port above the heating portion and with a gas supply port below the heating portion so that the gas circulate in a direction opposed to the traveling direction of a conducting strand passing therethrough, whereby said conductive strand is heated and cross-linked while residue emitted from the coating material of said conductive strand is effectively removed.